Drainage-casing for culverts, drain-tiling, wells, &amp;c.



DRAINAGE CASING FOR CULVERTS, DRAIN TILING, WELLS, &c.

APPucATxoN FILED mum-1914 LMQQ.. l Patented M1125, 1916.

237;/6/7 for" VAI\`I'I)IRJ?JV SMITH OF. SAN MATEO. CALIFORNIA.

DRAInAGE-ciisrivs roacunvnnrs, DnaIN-,Tinmd WELLS, aw.

rieaese.

T o all whom it may concern.' 4

Be it known that I, ANDREW SMITH, a

citizen of the United States, residing at Mateo, in the vcounty 'of` San'Matefo l State of California, have invented certain" dated May 20, 1913, and 1,105,539, dated July 28, 1914, and it is my present purpose to disclose and claim a casing having narrow draining slots which are formed by shearing the metal and pressing the alternate metal strips between the sheared slits in one direction forming projections on one side of the sheet, the opposite side of the sheet being smooth. When tubular casings or pipes, formed with the projections or strips of metal extending outwardly, are surrounded with earth, each of the projections forms an arch to support the earth and keep it away from the adjacent slots.

In the accompanying drawingswFigure 1, is a longitudinal side elevation of a drainage casing embodying my invention, the casing being corrugated and one end being tapered and the opposite end being reinforced by having the metal returned upon itself and both ends having threads rolled therein so that the casing sections may be screwed together; Fig. 2 is a side elevation partly in section of a similar drainage casing and the ends being provided with cut threads for a connecting collar; Fig. 3, is a side elevation of a drainage casing in which the projections between the slits extend inwardly, leaving the exterior of the casing smooth and unobstructed, the ends being internally threaded to receive a connecting collar; and Fig. 4 is an enlarged detail view showing the projections and slots.

The slots or perforations are formed by shearing .the metal to form a series of parallel slits and forcing alternate strips of metal between the slits beyond the plane of the metal forming projections. As shown in Fig. 4, each projection 3, forms an arch member, the intermediate strips 5, which remain in the plane of the sheet constituting Specification Letters ste-11t- Patented Jan-.25, 1916.

Applicationaieaauiy23,1912i.y sriainaesaew.

'brace members or struts. The slots 6 are formed betweentheedges of the adjacent strips., vVhen the drainage casing Al, is placed in theearth', theprojections or arch members 3 bear against the earth receiving the thrust or pressure, while the alternate strips 5 serve as tension or tie-members, thereby forming a very rigid and strongly braced struc-ture around the perforated portion of the casing.

Vhen it is desired that the casing shall be exceedingly rigid, as for culverts which must support heavy pressures and for well. curbingused at great depths, the plain im perforate portions 8, intermediate the perforated portions may be corrugated as shown in Fig. 1.

The casing units may be united to form a continuous casing by flaring and tapering the opposite ends respectively and rolling threads in the metal so that they may be screwed together. In Fig. l, I have shown the metal returned upon itself at the flared end 9, before being threaded to form a reinforcement. In Fig. 2, I have shown the ends provided with cut threads and a collar 10, interiorly threaded to form a union.

Vhile the casings shown in Figs. 1 and 2, with the outwardly projecting strips present little external obstruction and have the advantage of presenting a smooth unobstructed interior wall, there are conditions where a perfectly smooth exterior wall is desirable, as when a casing is to be driven through a restricted channel. Such a casing may be formed by having the projections 3, extend inwardly as illustrated in Fig. 3. In such cases the casing units may be united without obstruction by means of an exteriorly threaded collar 12, which screws into internal threads in the ends of the casing. I prefer to arrange the series of parallel slots and projecting strips in annular sets, with intervening annular imperforate portions, but it is evident that these portions may extend spirally around the casing as in my prior Patent 1,055,674, dated March 11, 1913, or in staggered or other relation.

I claim- 1. A drainage casing comprising a cylindrical sheet metal body having a plurality of sheared slits, the alternate strips of metal between said slits projecting beyond the plane of the sheet metal body and having both ends connected therewith, and the lindrical sheetklnetal body having a plurality of sheared slits, the alternate Vstrips of metal between said slits projecting beyond ing both ends connected therewith, and

forming slotsbetween its opposite edges the plane of the sheet metal body and hav- I and the edges of the adjacent strips, the wall of the casing on the opposite side from said projecting strips being substantially 'smooth and unobstructed.

In testlmony whereof I aiix my signature 15 in presence of two witnesses.

v ANDREW SMITH. Witnesses:

E. C. BROWN, K. HARTIG.

Conies of this patent may bey obtained for five cents each, by addressing the Commissioner of Patents. i Washington, D. C. 

